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Fluorescent carbon nanoparticle hybrids: synthesis, properties and applications
The development of materials in nanoscale morphologies with novel compositions is one of the major focuses of nanoscience and technology, as these materials are imbibed with unique properties that make them suitable for specific applications in a large variety of fields. Combining two or more chemically distinct constituents into a single nanostructure helps to attain desirable attributes of physical and chemical responses that can be efficiently utilized for specific applications. Hybrid nanomaterials constituted as a combination of multiple components into single nanostructures are known to showcase the properties of the individual components in tandem or synergy. Novel functionalities are also known to arise from integrating Fluorescent carbon nanoparticles (FCNPs) with other counterparts. FCNPs, when combined with other materials to form nanohybrids, provide copious functional attributes due to their inherent properties and the augmentation in properties due to the presence of the other materials. Integrating hybrid counterparts with FCNs improves the functional properties, which can be utilized for various applications such as photocatalysis, bioimaging, bio/chemo sensing, and many more. Herein we present an overview of recent and relevant works related to the synthesis, properties, and applications of fluorescent carbon nanoparticle (FCNP) hybrids. Various synthetic routes of FCNP hybrids via physical and chemical methods are summarized. The properties of the hybrid systems and the influence of hybridization on the properties are discussed. Applications of FCNP hybrids in various fields are also discussed in detail. 2025 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies. -
Fluorescence diffuse optical tomography: Synthesis, characterization and imaging of a novel target specific near infra-red contrast agent for breast cancer detection /
A paradigm shift is seen for cancer treatment since many decades in developing safe and efficient techniques to prevent, detect, treat and cure cancer worldwide. However, there is still a long way to stabilize the rate of cancer occurrence. Breast cancer is found to be among the top three cancer types in terms of incidence and fifth in terms of mortality. An estimate of 2.1 million new cases of breast cancer was recorded in the International Agency for Research on Cancer [IARC] Report 2018. Close to a half (43.6%) of all breast cancers were diagnosed within the Asia-Pacific region (approximately 911014 cases), with the greatest number of those occurring in China, Japan and Indonesia. Although the prognosis is relatively favorable, at least in more developed countries, early diagnosis is the lifesaver. Diffuse Optical Tomography (DOT) is one of the emerging diagnostic tools for early detection of breast cancer. It uses near infra-red (NIR) light to probe human soft tissues and is capable of continuous monitoring of the patient. DOT is cheaper, compact and uses non-ionizing radiation unlike its counterparts like CT-Scan, Mammogram and PET scan. The potential of DOT can be enhanced by using a NIR exogenous contrast agents, and the system is known as Fluorescence-DOT (FDOT). Indocyanine Green (ICG) is a popular FDA approved dye available in the market which is explored for cancer detection using FDOT. But, with its non-specific nature, there was a need for a specific and functionally orientated dye to further improve the efficacy of FDOT imaging. -
fluorescence diffuse optical tomography : Synthesis characterization and imaging of a novel target specific near infra-red contrast agent for breast cancer detection
Contrast agents are finding profound application in optical imaging of breast cancer for an early detection. In the present work, a novel estrogen receptor (ER) targeted near infra-red fluorescent dye conjugate was synthesized, referred to as Novel Dye Conjugate (nDC) hereafter. nDC is a conjugate of 17and#946;-estradiol with a derivative of indocyanine green dye, bis-1,1-(4-sulfobutyl) indotricarbocyanine-5-carboxylic acid, sodium salt. Structural composition of nDC was validated using Liquid Chromatography Mass Spectrometry (LC-MS) and Hydrogen-1 Nuclear Magnetic Resonance (1H-NMR) technique. MCF-7 and MDA MB 231 Cell lines studies proved the special biding ability of nDC with estrogen receptor positive breast cancer cell lines and its photophysical properties were verified to be in near infrared region (NIR). Similar studies were conducted on ER expressing cancerous tissues like Non-Invasive Ductal Carcinoma, Non-Invasive Lobular Carcinoma, Non-Invasive Adenocarcinoma and Non-Invasive Medullary Carcinoma. In all the above tissues, nuclear level ER binding of nDC was observed leading to the validations of the unique binding properties of the novel dye. Mathematical modeling for tumor to background mapping using nDC was carried out through Fluorescence Diffuse Optical Tomography (FDOT) simulations. Simulation results were also validated using silicone phantom experiments. An array of 8*8 boundary data was collected using frequency domain-FDOT system which was setup indigenously. Commercially available fluorescent dye Indocyanine Green (ICG) was used in the present study for comparative analysis with nDC. When compared to ICG, proposed dye had 1.5-fold higher target to background contrast with respect to fluorescent lifetime in both simulation and phantom studies. Similarly proposed novel dye had a two-fold higher target to background contrast with respect to fluorophore absorption. Above results proved the superiority of nDC compared to ICG on target(tumor) to background ratio enhancement. -
Fluorescence bioimaging applications of europium-doped strontium aluminate nanoparticles
Fluorescence bioimaging is widely used for physiological studies to visualise intercellular molecular events due to its highly selective, sensitive, and non-destructive nature. However, its application in in vivo live imaging is often limited by the scarcity of biocompatible fluorescent probes possessing optimal properties. Our study focuses on developing europium-based nanoparticles for in vivo bioimaging, especially imaging of plants. Eu-doped strontium aluminate nanoparticles were synthesised through a conventional solid-state reaction. Structural characterisation of samples using XRD confirmed the prevalence of SrAl2O4 as the prominent phase. The FTIR spectrum, SEM and TEM images were recorded for further characterization. Photoluminescence studies showed orange red emission of sample. The antibacterial activity of the nanophosphors was studied, demonstrating no antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. Furthermore, in vitro cytotoxicity studies conducted using Neuro-2A cells showed no indications of cytotoxicity associated with europium doped strontium aluminate nanoparticles. When incorporated into the plant tissue culture medium, these nanoparticles were found to have no effect on seed germination and plant growth, and it demonstrated no phytotoxicity. Imaging studies have shown the uptake of nanoparticles by plants and their subsequent transport through the vascular system. Our results emphasise the direct integration of nanophosphors into plant tissues from the growth medium, eliminating the necessity for traditional staining methods in fluorescence bioimaging. Incorporation of nanophosphors into living organisms holds promise for non-invasive and long-term fluorescence imaging, with potential applications in biological studies and diagnostics. The outstanding fluorescence properties and biocompatibility of europium doped strontium aluminate nanoparticles broaden its potential for various applications in fluorescence bioimaging. 2024 Elsevier Ltd and Techna Group S.r.l. -
Fluorescein Based Fluorescence Sensors for the Selective Sensing of Various Analytes
Fluorescein molecules are extensively used to develop fluorescent probes for various analytes due to their excellent photophysical properties and the spirocyclic structure. The main structural modification of fluorescein occurs at the carboxyl group where different groups can be easily introduced to produce the spirolactam structure which is non-fluorescent. The spirolactam ring opening accounts for the fluorescence and the dual sensing of analytes using fluorescent sensors is still a topic of high interest. There is an increase in the number of dual sensors developed in the past five years and quite a good number of fluorescein derivatives were also reported based on reversible mechanisms. This review analyses environmentally and biologically important cations such as Cu2+, Hg2+, Fe3+, Pd2+, Zn2+, Cd2+, and Mg2+; anions (F?, OCl?) and small molecules (thiols, CO and H2S). Structural modifications, binding mechanisms, different strategies and a comparative study for selected cations, anions and molecules are outlined in the article. 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Flow of nanoliquid past a vertical plate with novel quadratic thermal radiation and quadratic Boussinesq approximation: Sensitivity analysis
The effects of quadratic thermal radiation and quadratic Boussinesq approximation are investigated on the heat transport of a 36 nm Al2O3 ? H2O nanofluid over a vertical plate. The modified Buongiorno model is used in the analysis that includes the effectual thermophysical properties of the nanofluid and the key slip mechanisms. Experimentally verified correlations are used for the thermophysical properties. The reduced nonlinear differential problem is solved numerically by the Finite Difference Method (FDM). Flow profiles are displayed and analyzed for changes in dimensionless parameters. Further, the heat transfer flux at the wall is analyzed for interactive impacts of the buoyancy ratio, Brownian random motion, and thermophoresis parameters using the face-centered Central Composite Design (CCD) of the Response Surface Methodology (RSM). A sensitivity analysis is carried out for the heat transfer flux of the nanoliquid. Quadratic thermal radiation was found to improve the temperature profile. Furthermore, the mechanisms of Brownian random motion and thermophoresis have a negative sensitivity towards the rate of heat transfer. In various thermal applications like solar collectors, the density variation in terms of temperature differences is significantly high. Such phenomena can be accurately modeled by utilizing the quadratic Boussinesq approximation and the novel quadratic thermal radiation aspect. 2020 Elsevier Ltd -
Flow of nanofluid past a stretching cylinder subject to Thompson and Troian slip in the presence of gyrotactic microorganisms
Incorporating the Thompson and Troian slip condition, this work studies the bioconvective flow of a nanofluid past a vertically stretching cylinder. The Thompson and Troian slip deals with the molecular scale interactions at the solidfluid interface, which plays a pivotal role in the fluid flow analysis. This study helps in understanding the behaviours of fluid flow in the presence of non-linear slip past a vertically stretching cylinder. The corresponding partial differential equations (PDEs) for momentum, energy, concentration of nanoparticles, and concentration of microbes are developed using Buongiornos model. A suitable similarity transformation is then applied to these PDEs, converting them into a set of ordinary differential equations (ODEs). The RungeKuttaFehlberg (RKF-45) method is utilized to calculate the numerical solution of the resulting ODE problem. The results demonstrate that the interaction of slip conditions, viscous dissipation, heat source, and bioconvection causes complex flow patterns and heat transfer characteristics. These observations are extremely relevant for applications including better oil recovery procedures, biomedical engineering, and microfluidic devices where exact control over nanofluid behaviour is necessary. Some of the major observations of the study include the enhancement of the temperature in the nanofluid for higher Eckert numbers, control of fluid flow through an external magnetic field, and Peclet number significantly decreased the motile density in the nanofluid. The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024. -
Flow Cytometry Analysis of In Vitro Induced Polyploidy in Plants
Polyploidy is the condition of having more than two sets of chromosomes. The mechanism of polyploidy helps in deriving special traits like an increase in biomass, an increase in the size of various organ systems, and secondary metabolite content for the progeny. Various chemical compounds (colchicine, trifluralin, and oryzalin) that have the capacity to alter the mitotic cycle were used for the purpose of inducing polyploidy. Various techniques, such as counting of chromosome number, chloroplast number, determination of pollen diameter, and estimation of leaf stomatal density and size, were developed to analyze the polyploidy of the plants. However, these methods are not reliable for their regular use. Thus, of all the above-mentioned approaches, the estimation of ploidy level by flow cytometry (FCM) has been the most popular over the last few decades. Flow cytometry is now extensively used for the verification of haploidy, aneuploidy, and polyploidy. The ease of sample preparation, fast acquisition, and accurate measurements have made the method popular in the domains of plant cell biology, systematics, evolution, genetics, and biotechnology. The current chapter discusses the induction of polyploidy and its importance in plant breeding. It also emphasizes the importance of FCM in the analysis of polyploidy and enumerates the various polyploidy studies involving the application of FCM. 2023, Bentham Science Publishers. -
Flow and heat transport of nanomaterial with quadratic radiative heat flux and aggregation kinematics of nanoparticles
A numerical study of flow and heat transport of nanoliquid with aggregation kinematics of nanoparticles is carried out using the modified Buongiorno model (MBM). The MBM model is composed of random motion nanoparticles, heat diffusion of nanoparticles, and effective properties of nanoliquids. The effects of quadratic variation of density-temperature (quadratic convection), and the quadratic Rosseland thermal radiation are also studied. Inclined magnetism is also taken into account. The aggregation kinematics of nanoparticles is simulated using the modified Krieger-Dougherty model for dynamic viscosity and the modified Maxwell model for thermal conductivity. The main system of nonlinear partial differential equations is solved using the similarity technique and the finite difference method-based algorithm (FDM). The consequence of several key parameters on velocity, nanoparticle volume fraction, wall heat flux, and temperature are found in two cases, namely weak convective heating and strong convective heating. The study reveals that the suspension of the nanoparticles increases the thermal conductivity and, thus, improves the temperature and reduces the heat flux at the plate. The structures of the thermal and velocity surface layer are higher in the case of strong convective heating, while in the case of weak convective heating, the nanoparticle volume fraction layer is thicker. 2021 Elsevier Ltd -
Flourishing and work flow among working adults: A positive investigation from India
The demands in today's organizations are only growing at peaking high levels where turnover and burnout sets out to be major factors that challenge productivity. This is supported by previous findings which have identified turnover and burnout as a consequence of job demands. In today's demanding era of workforce, capacity to work effectively is a key component of employee's health, well-being and growth. Positive emotional and mental state of employees is a predictor of positive organization which will result in high performance, wellbeing and a conducive environment to flourish. Present study deals with workflow and its relationship with employee`s flourishing. This paper aims to explore the relationship between flourishing and experiences of work flow among working adults (n=105). Relationship among variables was analyzed through correlation and regression analysis. Results indicate that there is significant positive correlation between flourishing and experience of work flow (r (105) = 0.49, p<.01) and experience of work flow predicts the flourishing among employees. 2021 Ecological Society of India. All rights reserved. -
Floral waste as a potential feedstock for polyhydroxyalkanoate production using halotolerant Bacillus cereus TS1: optimization and characterization studies
The versatile properties and high degree of biodegradability of polyhydroxyalkanoates (PHA) have made them the ideal candidate for biomedical and other applications. Although extensive research on PHA-producing bacterial isolates from terrestrial environments is documented in the available literature, the potential of marine bacterial isolates in PHA production remains less explored and offers a great scope for future research. This research work primarily focuses on isolation and characterization of PHA-producing bacterial isolates from samples collected from coastal areas of Kerala, India. Furthermore, the possibility of PHA production from the most potential isolate Bacillus cereus TS1 using jasmine waste hydrolysate-based media was explored in this study. The utilization of floral waste hydrolysate (FWH) for PHA fermentation is not widely discussed in the available literature and is the major novelty factor of this research work. Under optimized conditions of glucose (1.2% w/v), yeast extract (0.15% w/v), NaCl (5.02% w/v), and incubation period (60h), a maximum PHA yield of 1.13g/L was achieved. The characterization of PHA polymer was done using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Thus, this research work integrates floral waste valorisation with microbial biopolymer production and highlights an innovative approach for sustainable development. The scale of this method on an industrial scale in future may prove helpful in the cost-effective production of PHA using cheap raw materials. Graphical Abstract: [Figure not available: see fulltext.]. 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature. -
FloodWatch: Suggesting an IoT-Driven Flood Monitoring and Early Warning System for the Flood-Prone Cuddalore District in the Indian State of Tamilnadu
Floods continue to pose significant threats to communities worldwide, causing loss of life, property damage, and disruption of vital services. Timely and accurate flood monitoring and early warning systems play a critical role in mitigating these impacts. This chapter presents FloodWatch, an innovative IoT-based flood monitoring and early warning system designed to enhance community resilience and response capabilities for the Cuddalore district, classified as one of the multi-hazard-prone districts of Tamilnadu. The Cuddalore district has a coastal line of 68 km, hence it is vulnerable to cyclones, and heavy rainfall, in turn causing floods. FloodWatch leverages the power of the Internet of Things (IoT) technology and provides real-time data collection, analysis, and dissemination for flood-related parameters. FloodWatch integrates a network of smart sensors strategically deployed in flood-prone areas, including rivers, streams, and urban drainage systems. These sensors continuously measure key variables, such as water level, rainfall intensity, weather conditions, and soil moisture content. The collected data is transmitted to a centralized cloud-based platform, where advanced data analytics and machine learning algorithms are employed to process and analyze the information. FloodWatch utilizes historical data and predictive modeling to assess the risk of flooding and generate accurate early warnings. Through intuitive interfaces and mobile applications, relevant stakeholders, including local authorities, emergency responders, and residents, receive real-time alerts and notifications, enabling timely decision-making and appropriate response actions. Key features of FloodWatch include its scalability, adaptability, and user-friendliness. The system can be easily customized to cater to different geographical and environmental conditions, ensuring its applicability in diverse regions. Additionally, FloodWatchs intuitive interfaces provide actionable insights in a visually comprehensible manner, facilitating effective communication and community engagement. The implementation of FloodWatch offers several notable benefits, including improved flood preparedness, reduced response time, and enhanced disaster management. By equipping communities with the tools to monitor, predict, and respond to floods, FloodWatch contributes to minimizing the impact of flood-related disasters, ultimately fostering greater resilience and safeguarding lives and property. FloodWatch represents a significant advancement in flood monitoring and early warning systems, harnessing IoT technology to provide accurate and timely information to communities at risk. This chapter highlights the architecture, functionality, and advantages of FloodWatch, underscoring its potential to enhance resilience and contribute to more effective flood management strategies on a global scale. 2025 selection and editorial matter, A. Daniel, Srinivasan Sriramulu, N. Partheeban, and Santhosh Jayagopalan; individual chapters, the contributors. -
Floating rafters for wetland treatment /
Patent Number: 351985-001. Applicant: S. Shrimathy. -
Flipped Classroom Strategy in Online Teaching: Challenges Faced by Higher Education Teachers
Flipped classroom model has gained increasing interest among university teachers in recent years [1] (Stohr et al.). The reason for its popularity is attributed to its bearing on Vygotskys constructivism theory and for the student centered approach [2] (Ziling Xu et al.). Countries in the world are affected by COVID-19 including India. Hence higher education institutes have begun their online classes. Flipped classroom teaching has been quite prevalent in Indian higher education recently. Online class initiation from higher education institutes in India has pushed faculty members to teach online and faculty have begun flipped classroom teaching online. Flipped classroom teaching in online differs from the face to face mode. There are challenges and issues while using flipped classroom in online mode by the faculty members of higher education. This leads to the present study to find out the challenges of flipped classroom teaching in online mode by teachers of higher education. The present study adopted qualitative research method. Structured interviews and focus group discussion were conducted to answer the research question. Study was able to discuss the challenges of flipped classroom in online mode. These challenges are to be dealt with by the stake holders to bring teaching efficacy. The Author(s), under exclusive license to Springer Nature Switzerland AG 2025. -
Flight Arrival Delay Prediction Using Deep Learning
This project is aimed to solve the problem of flight delay prediction. This problem does not only affect airlines but it can cause multiple problems in different sectors i.e., commercial (Cargo aviation), passenger aviation, etc. There are a number of reasons why flights can be delayed, with weather being the main one. Our goal in this study is to forecast flight delays resulting from a variety of reasons, such as inclement weather, delayed aircraft, and other issues. The dataset gives itemized data on flight appearances and postponements for U.S. air terminals, classified via transporters. The information incorporates metrics such as the number of arriving flights, delays over 15 minutes, cancellation and diversion counts, and the breakdown of delays attributed to carriers, weather, NAS (National Airspace System), security, and late aircraft arrivals. For the purpose of predicting flight delays, the outcomes of several machine learning algorithms are examined, including Ridge, Lasso, Random Forest, Decision Tree, and Linear regression. With the lowest RMSE score of 0.0024, the Random Forest regressor performed the best across all scenarios. A deep learning model using a dense neural network is built to check how accurate a deep learning model will be while predicting the delay and the result was an RMSE score of 0.1357. 2024 IEEE. -
Flexible Teaching - Learning Systems in Indian Higher Education System through Technology - A Study on Demographic Impact
International Journal of Computer Application Vol. 5, Issue 2, pp 178-182, ISSN No. 2250-1797 -
Flexible polymer composite films incorporated with Li-ion/reduced graphene oxide: excellent optical and photoluminescence performance
A flexible polymer composite film (PL-rGO) was prepared from reduced graphene oxide (rGO) (derived from graphite) and lithium phosphate (Li3PO4) incorporated in a pale yellow colored polystyrene sulfonic acid (PSSA) polymer by solution casting method. The resulting flexible translucent PL-rGO composite films were obtained with smooth surface and thickness in the range of 23m. The optical and photoluminescence properties of PL-rGO were explored in the present study. The intensity of photoluminescence spectra at excitation band ? 320nm increases with significant broadening with varying concentration of rGO in the matrix. The evaluated direct and indirect energy bandgap of PL-rGO composite from optical absorbance is in the range of 3.06 ~ 3.26eV. These results from optical properties for PL-rGO composite indicate the accurate tailoring of the composite by changing the rGO volume fraction. 2019, King Abdulaziz City for Science and Technology. -
Flexible Nanogenerators Based on Enhanced Flexoelectricity in Mn3O4 Membranes
Atomically thin, few-layered membranes of oxides show unique physical and chemical properties compared to their bulk forms. Manganese oxide (Mn3O4) membranes are exfoliated from the naturally occurring mineral Hausmannite and used to make flexible, high-performance nanogenerators (NGs). An enhanced power density in the membrane NG is observed with the best-performing device showing a power density of 7.99mWm?2 compared to 1.04Wm?2 in bulk Mn3O4. A sensitivity of 108mVkPa?1 for applied forces <10N in the membrane NG is observed. The improved performance of these NGs is attributed to enhanced flexoelectric response in a few layers of Mn3O4. Using first-principles calculations, the flexoelectric coefficients of monolayer and bilayer Mn3O4 are found to be 50100 times larger than other 2D transition metal dichalcogenides (TMDCs). Using a model based on classical beam theory, an increasing activation of the bending mode with decreasing thickness of the oxide membranes is observed, which in turn leads to a large flexoelectric response. As a proof-of-concept, flexible NGs using exfoliated Mn3O4 membranes are made and used in self-powered paper-based devices. This research paves the way for the exploration of few-layered membranes of other centrosymmetric oxides for application as energy harvesters. 2023 Wiley-VCH GmbH. -
Flexible and cost-effective cryptographic encryption algorithm for securing unencrypted database files at rest and in transit
To prevent unauthorized access to the databases and to ensure that the data of the databases is protected from intruders and insiders, the data is being encrypted at the storage locations. The same goal is achieved with Transparent Data Encryption, a feature that can be found in almost all database products. However, it has been observed that the non-datafiles are being ignored and there is no standard encryption for them like there is for datafiles. Moreover, there was no standard algorithm to encrypt them without relying on third-party tools. Therefore, This study provides a robust algorithm to perform the encryption. This presentation also describes the importance of non-datafiles encryption, and how some non-datafiles can pose a threat to data and infrastructure without encryption. The practical implementation of the non-data file encryption algorithm shows the authentic results. Further, unlike existing algorithms, the proposed algorithm gives the file owner full control over the encryption logic. In the encryption process, two levels of encryption logics are combined with a passcode lock, while the same combination of two levels of reversing encryption and passcode is used in the decryption process to convert encoded data back into text format. 2022 The Author(s) -
Flavonol based surface modification of doped chalcogenide nanoflakes as an ultrasensitive fluorescence probe for Al3+ ion
A highly selective novel fluorescent probe was prepared by using surface modified ZnS:Mn nanoparticles, functionalized with morin, a flavonol. SEM investigations of the heterostructures prepared using wet chemical precipitation technique revealed a nanoflake type of morphology. HR-TEM and powder XRD analysis confirmed the crystalline planes corresponding to Wurtzite ZnS. The functionalized nanoparticles were characterized using Raman, XPS and FTIR which confirms the binding of morin to the nanoparticles via surface coordination. The prepared probe selectively interacts with Al3+ ions which has been used as an ultrasensitive analytical tool for determination of Al3+ ions. A major advantage of the proposed method is that the other metal ions closely associated with Al3+ did not interfere with the analysis. The detection limit and the quantitation limit were found to be 0.07 nM and 0.20 nM respectively with a linear dynamic range 0.20 nM80 nM. The method was successfully applied to environmental water samples and other complex matrices. 2017 Elsevier B.V.