A uracil nitroso amine based colorimetric sensor for the detection of Cu²⁺ ions from aqueous environment and its practical applications

A simple uracil nitroso amine based colorimetric chemosensor (UNA-1) has been synthesized and screened for its cation recognition ability. Sensor UNA-1 exhibited a high sensitivity and selectivity towards Cu²⁺ ions in aqueous medium in the presence of a wide range of other competing cations (Ag⁺, Al³⁺, Ba²⁺+, Ca²⁺, Cd²⁺, Co²⁺, Cr³⁺, Cs⁺, Fe²⁺, Fe³⁺, Li⁺, Mg²⁺, Mn²⁺, Na⁺, Ni²⁺, Pb²⁺, Zn²⁺, Hg²⁺ and Sr²⁺). With Cu²⁺, the sensor UNA-1 gave a distinct color change from colorless to dark yellow by forming a complex of 1:1 stoichiometry. Furthermore, sensor UNA-1 was successfully utilized in the preparation of test strips and supported silica for the detection of Cu²⁺ ions from aqueous environment

Experimental investigation on the susceptibility of minimal networks to a change in topology and number of oscillators

Understanding the global dynamical behaviour of a network of coupled oscillators has been a topic of immense research in many fields of science and engineering. Various factors govern the resulting dynamical behaviour of such networks, including the number of oscillators and their coupling schemes. Although these factors are seldom significant in large populations, a small change in them can drastically affect the global behaviour in small populations. In this paper, we perform an experimental investigation on the effect of these factors on the coupled behaviour of a minimal network of candle-flame oscillators. We observe that strongly coupled oscillators exhibit the global behaviour of in-phase synchrony and amplitude death, irrespective of the number and the topology of oscillators. However, when they are weakly coupled, their global behaviour exhibits the intermittent occurrence of multiple stable states in time. In addition to states of clustering, chimera, and weak chimera, we report the experimental discovery of partial amplitude death in a network of candle-flame oscillators. We also show that closed-loop networks tend to hold global synchronization for longer duration as compared to open-loop networks. We believe that our results would find application in real-life problems such as power grids, neuronal networks, and seizure dynamics.Comment: 10 pages, 8 figures, not submitted anywher

Bio medical Waste Management : A Case Study of Pune City

There are number of hospitals in all over the India which emits the Bio medical waste in large quantities in the form of contaminated and non-contaminated waste which are hazardous to health. Proper handling, treatment and disposal of Bio medical waste play a vital role in hospital infection controlled program. Unfortunately lack of adequate training, improper management, illiteracy about handling and awareness and no execution of Bio medical handling rules leads to staid health and environmental apprehension. Careless handling and disposal of these infectious wastes may lead to serious threat to life human as well as animals. This study explains the existing information about bio medical waste management, segregation, transportation, storage, treatment and disposal. Also this study explains lacunas of existing management system of bio medical waste, the recommendations and suggestions of bio medical waste management

Dynamics of Minimal Networks of Limit Cycle Oscillators

The framework of mutually coupled oscillators on a network has served as a convenient tool for investigating the impact of various parameters on the dynamics of real-world systems. Compared to large networks of oscillators, minimal networks are more susceptible to changes in coupling parameters, the number of oscillators, and network topologies. In this study, we systematically explore the influence of these parameters on the dynamics of a minimal network comprising Stuart-Landau oscillators coupled with a distance-dependent time delay. We examine three network topologies: ring, chain, and star. Specifically, for ring networks, we study the effects of increasing nonlocality from local to global coupling on the overall dynamics of the system. Our findings reveal the existence of various synchronized states, including splay and cluster states, a partially synchronized state such as chimeric quasiperiodicity, and an oscillation quenching state such as amplitude death in these networks. Moreover, through an analysis of long-lived transients, we discover novel amplitude-modulated states within ring networks. Interestingly, we observe that increasing nonlocality diminishes the influence of the number of oscillators on the overall behavior in these networks. Furthermore, we note that chain networks, unlike ring networks, do not exhibit perfect synchrony among the coupled oscillators. In contrast, star networks demonstrate greater stability and are unaffected by the number of oscillators within the network. The insights from this study deepen our understanding of the dynamics of minimal networks and have implications for various fields, ranging from biology to engineering.Comment: 14 pages, 11 figure

Chemosensor for micro to nano-molar detection of Ag+ and Hg2+ ions in pure aqueous media and its applications in cell imaging

The pyridine substituted thiourea derivative PTB-1 was synthesized and characterized by spectroscopic techniques as well as by single crystal X-ray crystallography. The metal ion sensing ability of PTB-1 was explored by various experimental (naked-eye, UV-Vis, fluorescence, mass spectrometry and 1H NMR spectroscopy) and theoretical (B3LYP/6-31G**/LANL2DZ) methods. PTB-1 exhibited a highly selective naked-eye detectable color change from colorless to dark brown and UV-Vis spectral changes for the detection of Ag+ with a detection limit of 3.67 µM in aqueous medium. The detection of Ag+ ions was achieved by test paper strip and supported silica methods. In contrast, PTB-1 exhibited a 23-fold enhanced emission at 420 nm in the presence of Hg2+ ions with a nano-molar detection limit of 0.69 nM. Finally, the sensor PTB-1 was applied successfully for the intracellular detection of Hg2+ ions in a HepG2 liver cell line, which was monitored by use of confocal imaging techniques

The Multicorder: A Handheld Multimodal Metabolomics-on-CMOS Sensing Platform

The use of CMOS platforms in medical point-of-care applications, by integrating all steps from sample to data output, has the potential to reduce the diagnostic cost and the time from days to seconds. Here we present the `Multicorder' technology, a handheld versatile multimodal platform for rapid metabolites quantification. The current platform is composed of a cartridge, a reader and a graphic user interface. The sensing core of the cartridge is the CMOS chip which integrates a 16×16 array of multi-sensor elements. Each element is composed of two optical and one chemical sensor. The platform is therefore capable of performing multi-mode measurements: namely colorimetric, chemiluminescence, pH sensing and surface plasmon resonance. In addition to the reader that is employed for addressing, data digitization and transmission, a tablet computer performs data collection, visualization, analysis and storage. In this paper, we demonstrate colorimetric, chemiluminescence and pH sensing on the same platform by on-chip quantification of different metabolites in their physiological range. The platform we have developed has the potential to lead the way to a new generation of commercial devices in the footsteps of the current commercial glucometers for quick multi-metabolite quantification for both acute and chronic medicines

THE PREVALENCE AND IMPACT OF AFLATOXIN CONTAMINATION IN NUTS AND DRY FRUITS

Aflatoxins are toxic, carcinogenic secondary metabolites produced by Aspergillus flavus, and they are responsible for the contamination of nuts and dried fruits. The aim of the study was to determine the prevalence of aflatoxin contamination in nuts and dried fruits sold in different countries. Dried fruits could contain harmful mycotoxins, posing a risk to health. Fungi, which are integral components of the soil, cause contamination of many food products, including dried fruits and nuts. This fungal burden not only leads to the deterioration of these nutrients but is also responsible for mycoses and mycotoxicoses in consumers, especially immunocompromised individuals. The high burden of aflatoxigenic and drug-resistant fungi in edible products such as dried fruits and nuts poses an immediate threat to the human population and therefore requires rapid control. Aflatoxins were found in food and feed globally, and their economic impact was extensively studied. This review examined the risks of consuming moldy produce and the potential for infection by aflatoxigenic fungi. It also discussed the previous state of aflatoxin contamination in various countries worldwide. Aflatoxins were detected in a range of foods and feeds, with dried fruits (almonds, raisins) and nuts (peanuts, pistachios, walnuts, cashews, etc.) being the primary sources. This review also focuses on the impact of aflatoxin on the health

Modified Cantilever Arrays Improve Sensitivity and Reproducibility of Nanomechanical Sensing in Living Cells

Mechanical signaling involved in molecular interactions lies at the heart of materials science and biological systems, but the mechanisms involved are poorly understood. Here we use nanomechanical sensors and intact human cells to provide unique insights into the signaling pathways of connectivity networks, which deliver the ability to probe cells to produce biologically relevant, quantifiable and reproducible signals. We quantify the mechanical signals from malignant cancer cells, with 10 cells per ml in 1000-fold excess of non-neoplastic human epithelial cells. Moreover, we demonstrate that a direct link between cells and molecules creates a continuous connectivity which acts like a percolating network to propagate mechanical forces over both short and long length-scales. The findings provide mechanistic insights into how cancer cells interact with one another and with their microenvironments, enabling them to invade the surrounding tissues. Further, with this system it is possible to understand how cancer clusters are able to co-ordinate their migration through narrow blood capillaries